The present invention relates to a method and apparatus for processing thermal developable film. It particularly relates to a method and apparatus for employing a pre-process on the film to determine optimal conditions for a subsequent process.
In the conventional practice of color photography, silver halide film is developed by a chemical technique, requiring several steps consisting of latent image developing, bleaching, and fixing. While this technique has been developed over many years and results in exceptional images, the technique requires several liquid chemical solutions and precise control of times and temperatures of development. Further, the conventional silver halide chemical development technique is not particularly suitable for utilization with a compact developing apparatus. The chemical technique which is a wet processing technique also is not easily performed in the home or small office. Imaging systems that do not rely on conventional wet processing have received increased attention in recent years. Photothermographic imaging systems have been employed for producing silver images.
A method and apparatus for developing a heat developing film is disclosed in U.S. Pat. No. 5,587,767 to Islam et al. Summaries of photo thermographic imaging systems are published in Research Disclosure, Vol. 170, June 1978, Item 17029, and Vol. 299, March 1989, Item 29963.
Heat development color photographic materials have been disclosed in U.S. Pat. No. 4,021,240 to Cerquone et al and U.S. Pat. No. 5,698,365 to Taguchi et al, and commercial products such as Color Dry Silver supplied from Minnesota Mining and Manufacturing Co. and PICTROGRAPHY(trademark) and PICTROSTAT(trademark) supplied by Fuji Photo Film Co., Ltd. are known. Furthermore, U.S. Pat. No. 5,840,475 discloses an imaging element capable of providing a retained viewable image when imagewise exposed and heated.
A recent innovation in color negative film has made use of a thrust cartridge. Such cartridges are disclosed in U.S. Pat. No. 4,834,306 to Robertson et al and U.S. Pat. No. 5,003,334 to Pagano et al. The film contained in such a thrust cartridge may contain a magnetic layer that allows recording of information during manufacture, exposure, and development of the film. Such film is disclosed in U.S. Pat. No. 5,215,874 to Sakakibara. The film and cartridge may contain additional provisions for data storage such as DX bar code data and frame number bar code data. Such elements are disclosed in U.S. Pat. Nos. 5,032,854, 5,229,585, and 4,965,628. The thrust cartridge may also be made light-tight so that unexposed or imagewise exposed film that has been rewound into the cartridge may be stored without further exposure of the film within the cartridge. These thrust cartridge films have the advantage that they may be more easily manipulated for copying, digital reading, and storage.
U.S. Pat. No 6,048,110 to Szajewski et al. illustrates a further example of an apparatus for thermal development of thermal film using a thrust cartridge, with the apparatus including a magnetic reader and writer.
Writing of reference patches onto film to improve imaging system performance is known in the art. Such techniques for conventional wet process films are disclosed for example in U.S. Pat. No. 5,667,944xe2x80x94Reem et al. Similar techniques for dry process films are disclosed in U.S. application Ser. No. 09/206,914 filed Dec. 7, 1998. Further calibration patches are described in more detail by Wheeler et al U.S. Pat. No. 5,649,260, Koeng at al U.S. Pat. No. 5,563,717, by Cosgrove et al U.S. Pat. No. 5,644,647 and in combination with films intended for scanning by Sowinski et al U.S. Pat. No. 6,021,277.
A drawback with traditional approaches to processing film is that they do not provide for a consistent and accurate method of determining optimal processing conditions for thermally developed film.
The present invention provides for a method and apparatus for processing images, in which a pre-process of the film is used to determine optimum processing characteristics of the film for a subsequent second process.
The method of the present invention includes a first processing step of processing a thermal film to determine optimum processing characteristics of the thermal film; and a second processing step of processing the thermal film based on the optimum processing characteristics determined in the first processing step to develop images on the film.
The present invention further provides for an image processing system that comprises a processing section that is adapted to perform a test process on a thermal film to determine optimum processing characteristics of the thermal film and provide a processing signal indicative thereof. The processing section is further adapted to perform a subsequent full process on the thermal film to develop images on the film. The image processing assembly also comprises a controller that receives the processing signal and is adapted to modify the subsequent full processing of the film based on the determined optimum processing characteristics.
The invention further relates to processing method that comprises the steps of processing a thermal film at a minimum process temperature; scanning the processed thermal film at an illumination wavelength that does not cause an imagewise exposure of the film; determining optimum processing characteristics of the film based on information obtained from the scanning step; and performing a subsequent processing of the film based on the determined optimum processing characteristics.
The present invention further relates to a processing system that comprises a processing section adapted to process a photosensitive film at a minimum process temperature and is further adapted to perform a subsequent processing on the film to develop images on the film; a scanner that scans the film after the film has been processed at the minimum process temperature and before the film is subjected to the subsequent process to determine optimum processing characteristics of the film; and a controller adapted to modify the subsequent processing based on the determined optimum characteristics.
The present invention further relates to a film and processing system in which the film contains a test pattern that can be exposed during manufacture or prior to processing. The test pattern can be located on the film in an area that can be subjected to any suitable processing condition, including the low temperature initial process or the subsequent optimum processing temperature. Optical information extracted from the process test pattern can then be used to modulate a subsequent thermal process or modulate the digital image processing of the scanned images.